The present invention relates to an orthopedic supporting member, particularly an orthopedic supporting insert of a synthetic plastic material. The invention also relates to a method of manufacturing the orthopedic supporting member.
In the orthopedy, supporting members are known which must have different properties in their different zones. For example, in an orthopedic shoe insert with a supporting region for the central part of the foot and a heel region it is necessary that the heel region be elastically flexible and the supporting region be relatively stiff, but also elastic, and moreover after-deformable in correspondence with individual shapes or feet. These requirements must also be satisfied in other orthopedic supporting members, such as for example, cervical ortheses, peroneus splints, etc.
Orthopedic supporting members, particularly orthopedic shoe inserts of thermoplastic synthetic plastic material which are after-deformable are known. Particularly in the event of the orthopedic shoe inserts with the heel region, it is necessary for guaranteeing a sufficient support stiffness to select such a material thickness which causes an unpleasant so-called charge in the shoe and makes wearing of the shoe inconvenient. Because of the required material quantity and thickness, the product must be heavy and rigid, and in many cases also expensive. Zones with different properties to satisfy the respective requirements are difficult to implement. Zones, for example in the heel region in an orthopedic shoe insert, are ground thinner to render them different properties. The thinner zones are susceptible to breakage and particularly in a transition region to the central foot region to which the weight of a user is applied.
An orthopedic shoe insert is disclosed in the DE-OS No. 3,304,537, which is composed of a thermoplastic synthetic plastic material and maintains at the normal temperature of use its predetermined anatomically designed shape in elastic spring manner, while at higher temperature it is plastically deformable and maintains its acquired shape after cooling. The synthetic plastic material which is used here is a casting resin, particularly a glass fiber-reinforced acrylic casting resin. The reinforcement is formed by several layers of a hose tricot fabric. Approximately between 10 and 14 hose tricot fabric layers are used here. During the manufacture of this known shoe inserts, different intermediate layers of the glass fabric material are applied in a stepped manner, and the heel step surface can be made very thin with only a few layers. As a result of this, the heel step surface is less stiff than the other parts of the shoe insert. The method of manufacturing the above described shoe insert is extremely expensive. Different stiffnesses are provided by different thickness of the synthetic plastic material and by the number of the fabric inserts. Moreover, only a blank can be made which subsequently must be worked by grinding or milling.